import requests r = requests.post( "https://openrouter.ai/api/v1/chat/completions", headers={"Authorization": "Bearer " + OPENROUTER_KEY}, json={ "model": "stealth/union-alpha", "messages": [ { "role": "user", "content": "Hello!" } ] }, ) print(r.json())
const r = await fetch("https://openrouter.ai/api/v1/chat/completions", { method: "POST", headers: { Authorization: `Bearer ${process.env.OPENROUTER_KEY}`, "Content-Type": "application/json", }, body: JSON.stringify({ "model": "stealth/union-alpha", "messages": [ { "role": "user", "content": "Hello!" } ] }), }); console.log(await r.json());
curl -X POST https://openrouter.ai/api/v1/chat/completions \ -H "Authorization: Bearer $OPENROUTER_KEY" \ -H "Content-Type: application/json" \ -d '{"model":"stealth/union-alpha","messages":[{"role":"user","content":"Hello!"}]}'
OpenAI-compatible — swap the base URL and it works with your existing SDK.
| Type | Price |
|---|---|
| Output | |
| Model | Input | Output | Context | Best for |
|---|---|---|---|---|
Union Alpha This page | Agentic coding and long-context research | |||
| Coding + agents | ||||
| Deep reasoning + long-context agents | ||||
| Coding + agents | ||||
| Coding + agents |
Union Alpha is an unattributed “stealth” model published on OpenRouter as stealth/union-alpha. OpenRouter describes it as multimodal and built for research, coding and agentic workflows.
Nobody has claimed it. It is published without an attributed vendor, which is what “stealth” means on OpenRouter.
During the preview, yes. OpenRouter lists it at $0 per million input and output tokens, and OpenCode announced a free window of about one week.
OpenCode announced roughly one week from September 16, 2026. Neither platform has said what pricing applies once it closes.
262,144 tokens, as listed by OpenRouter. No maximum output length has been published.
Yes. OpenCode's announcement states it supports images, and OpenRouter lists it as multimodal.
OpenCode's announcement states there is no training on user data. Retention policies differ between hosts, so check the policy of whichever route you call it through.
The API accepts tools, tool_choice, stream, response_format, temperature, top_p and max_tokens.
None have been published by whoever built it. Figures circulating on social media are community measurements, not vendor data.
Yes — it is coming soon, and it will be free while the preview window lasts. You will be able to call it with the same key and the same OpenAI-compatible request shape as every other model in the catalogue.
